1. Field of the Invention
The present invention relates to a front structure of a vehicle, more specifically to a front structure of a vehicle for decreasing weight of a vehicle body with maintaining rigidity.
2. Discussion of the Related Art
A front structure of a vehicle contains left and right wheel aprons constituting left and right lateral walls of an engine compartment. Each of the wheel aprons extends approximately from a front end of the vehicle to a toe board in a lengthwise direction of the vehicle. The upper and lower ends of the wheel aprons are respectively connected to upper side frames and front side frames. Each wheel apron has a wheel arch protruding toward the engine compartment for accommodating a wheel therein. A suspension strut is accommodating in the wheel arch, and a strut tower for supporting a top end of the suspension strut is provided on the wheel arch. A suspension cross member is provided between the left and right front side frames. The suspension cross member supports lower ends of suspension lower arms and power units such as an engine and a transmission. A strut tower should have a relatively high rigidity to sufficiently support a load applied from a suspension or the like. Japanese Kokai Publication 10 (1998)-129523 may be briefly summarized as follows. FIG. 8 is a schematic cross sectional view of a strut tower structure. In the figure, an arrow F denotes a front direction of a vehicle.
A strut tower 102 is supported on a wheel apron 101 and has a lower end connected to a front side frame 103 and an upper end connected to an upper side frame 105. Strut tower reinforcing members 104 are provided at front and rear ends of the strut tower 102 in an approximately vertical direction. Namely, the reinforcing members 104 extend so as to cover the front and rear ends of the strut tower 102 along the convex shape of the wheel apron 101. The lower end of the strut tower reinforcing member 104 is connected to the front side frame 103 and the upper end thereof is connected to the upper side frame 105. By this configuration, the strut tower 102 can be firmly (rigidly) supported, so as to provide a rigid structure.
A load can be applied to the suspension cross member through the suspension and the power units and then transmitted to the left and right front side frames. Therefore, even if the rigidity itself is sufficient, it is also necessary to increase the connection strength of the suspension cross member and the front side frames. For this purpose, reinforcing members are applied to the connection parts between the suspension cross member and the front side frames, or the front side frames themselves are strengthened. Accordingly, it is possible that the weight of the vehicle is increased or that the structure becomes complicated.
Various loads can be applied to a vehicle body in many situations when the vehicle moves. Thus, a sufficient rigidity is required, especially to the front structure of the vehicle.
It is therefore a first object of the present invention to provide a front structure of a vehicle having an excellent rigidity in spite of its lightweight by eliminating additional reinforcing members and excluding a complex structure.
The first object of the present invention is achieved by a front structure of a vehicle, comprising a pair of symmetrically formed units, each comprising an upper side frame extending in a lengthwise direction of the vehicle; a front side frame extending in a lengthwise direction of the vehicle at a lower and inner position with respect to the upper side frame; a wheel apron extending in a lengthwise direction of the vehicle to provide a lateral wall of an engine compartment of the vehicle, an upper end and a lower end of the wheel apron being respectively connected to the upper side frame and the front side frame; a strut tower provided between the upper side frame and the front side frame and connected to the wheel apron; and a strut tower reinforcing member connecting the upper side frame and the front side frame, the strut tower reinforcing member forming a structure having a closed hollow cross section extending approximately in a vertical direction in cooperation with the strut tower; and a suspension cross member extending in a widthwise direction of the vehicle, the suspension cross member connecting the front side frame in each of the units to each other, the suspension cross member positioned in a lengthwise direction of the vehicle corresponding to a lower end of the structure having a closed hollow cross section in each of the units.
The first object the present invention is also be achieved by a front structure of a vehicle comprising a pair of symmetrically formed units, each comprising an upper side frame extending in a lengthwise direction of the vehicle; a front side frame extending in a lengthwise direction of the vehicle provided at a lower and inner position with respect to the upper side frame; a wheel apron extending in a lengthwise direction of the vehicle to provide a lateral wall of an engine compartment of the vehicle, an upper end and a lower end of the wheel apron being respectively connected to the upper side frame and the front side frame;
strut tower provided between the upper side frame and the front side frame and connected to the wheel apron; and a strut tower reinforcing member connecting the upper side frame and the front side frame, the strut tower reinforcing member forming a structure having a closed hollow cross section extending approximately in a vertical direction along the strut tower in cooperation with the wheel apron; and a suspension cross member extending in a widthwise direction of the vehicle, the suspension cross member connecting the front side frame in each of the units to each other, the suspension cross member positioned in a lengthwise direction of the vehicle corresponding to a lower end of the structure having a closed hollow cross section in each of the units.
A second object of the present invention is to provide the front structure of a vehicle wherein the rigidity of the structure having the closed hollow cross section, strut tower and the vehicle body is further improved by connecting a lateral end of the strut tower to a lateral end of the strut tower reinforcing member and to a lateral end of the wheel apron.
A third object of the present invention is to provide the front structure of a vehicle wherein the connection rigidity of the strut tower and the suspension cross member is further improved, which in turn increases the rigidity of the vehicle body by connect, a lower edge of the strut tower reinforcing member to the suspension cross member.
A fourth object of the present invention is to provide the front structure of the vehicle wherein the rigidity of the entire front structure of the vehicle is improved by further comprising a strut tower bar for connecting the strut tower in each of the units to each other.
A fifth object of the present invention is to provide the front structure of the vehicle wherein the strut towers are stably supported which increases the rigidity of the vehicle body by connecting the strut tower bar to the strut tower and to the upper side frame at a location with respect to a lengthwise direction of the vehicle corresponding to the structure having a closed hollow cross section.
A sixth object of the present invention is to provide the front structure of the vehicle wherein the strut towers are stably supported and the rigidity of the entire front structure of the vehicle is further improved, by further comprising a strut tower bar for connecting the strut tower in each of the units to each other, each free end of the strut tower bar having a first installation part and a second installation part, the first installation part being connected to the upper side frame, the second installation part being connected to an upper face of the strut tower, the strut tower bar positioned in a lengthwise direction of the vehicle corresponding to a closed hollow cross section.